འ in འཁོར་བ ?

[kirtu]

འ is a short a sound as in father?

But in འཁོར་བ this is pronounced kor-wa isn't it? So the འ is silent here but looking through the dictionary it doesn't seem to be the case usually that an initial འ is silent. Is there a rule for this?

Thanks!

Sorry about the flood of questions but my books are all in storage or I had to give them away and Tibetan language books don't come in Kindle versions yet. And after years of playing around I have finally started learning Buddhist Tibetan.

Kirt

[conebeckham]

Ah-Chung in the prefix position (Ngonjuk) is silent. Though it may "nasalize" the ending of a preceding syllable, at times, and depending on dialect.